University of Peradeniya, Peradeniya, LK

About W. S.

D. Kumaragamage

University of Winnipeg, MB, CA

About D.

Abstract

Beneficial management practices can be used to improve the crop productivity of tropical Alfisols. This study evaluated beneficial management practices to overcome the soil physical and chemical limitations for growing maize (Zea mays). The experiment was conducted in the Low Country Dry Zone (DL1b) on Reddish Brown Earth soil (Typic Rhodustalf). Four treatments; un-amended control (C), site specific fertilizer (SSF), biochar applied at 1 t/ha with SFF (BC+SSF) and rock powder applied at 10 t/ha with SSF (RP+SSF) were tested using maize as the test crop initially in the greenhouse and later in the field at DL1b for two growing seasons (2013 Yala and 2013/2014 Maha) for their effects on crop growth and soil fertility. Soil was neutral, non-saline, sandy clay loam in texture with comparatively high clay content (27%) and low in organic matter content (1.5%) and deficient in N, P, S, Ca, Zn, and Cu, initially. In the greenhouse, plant dry weight increased significantly with the addition of amendments i.e., fertilizers alone (SSF), or BC+SSF or RP+SSF. In the field study, no significant differences were observed for soil pH with the addition of amendments but biochar application significantly increased cation exchange capacity, organic matter, potentially mineralizable nitrogen and carbon management index. Rock powder+SSF and BC+SSF significantly increased the grain yield over the control in both seasons. Both labile and recalcitrant C were significantly higher in BC+SSF treatment than the others. Further, application of BC and RP had no significant impact on soil textural fractions and bulk density, yet in both seasons, BC+SSF application increased the aggregate stability greater than other treatments. The results of the field experiment suggest that biochar and rock powder with adequate nutrients effectively improved soil fertility and productivity.